Wang R Y, Ghabrial S A
Department of Plant Pathology, University of Kentucky, Lexington 40546.
Plant Dis. 2002 Nov;86(11):1260-1264. doi: 10.1094/PDIS.2002.86.11.1260.
The soybean aphid (Aphis glycines) was a poor vector (0.83% transmission) when the aphids were allowed overnight acquisition feed on Soybean mosaic virus (SMV)-infected soybean leaves. However, A. glycines was shown to be a very efficient vector (34.72% transmission) when individual aphids were allowed a 1-min acquisition probe on the same infected leaves used for the feeding treatment. Similar results were obtained with Myzus persicae and tobacco in transmission experiments of the potyviruses Tobacco etch virus (feeding: 1.36%; probing: 45.5%) and Tobacco vein mottling virus (feeding: 2.0%; probing: 47.5%). A reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to detect SMV in single soybean aphids using a pair of primers designed to amplify a 469-bp PCR fragment in the coding region of SMV coat protein. In contrast to the low transmission rate obtained with the soybean aphids that acquired virus through overnight feeding, RT-PCR detected SMV in 100% of these aphids. Interestingly, the rate of SMV detection by RT-PCR in aphids that were allowed a 1-min acquisition probe (31.67%) coincided with percent transmission (34.72%). The practical application of RT-PCR in detecting nonpersistently transmitted viruses and its implications for virus epidemiology are discussed.
当让大豆蚜（Aphis glycines）在感染大豆花叶病毒（SMV）的大豆叶片上取食过夜时，其作为传毒介体的效率很低（传毒率为0.83%）。然而，当让单头蚜虫在用于饲喂处理的相同感染叶片上进行1分钟的获毒刺探时，大豆蚜被证明是一种非常高效的传毒介体（传毒率为34.72%）。在马铃薯Y病毒属病毒烟草蚀纹病毒（取食：1.36%；刺探：45.5%）和烟草脉斑驳病毒（取食：2.0%；刺探：47.5%）的传毒试验中，用桃蚜和烟草也获得了类似结果。开发了一种逆转录聚合酶链反应（RT-PCR）检测方法，使用一对引物来扩增SMV外壳蛋白编码区的一个469 bp的PCR片段，以检测单个大豆蚜中的SMV。与通过过夜取食获得病毒的大豆蚜传毒率较低形成对比的是，RT-PCR在100%的这些蚜虫中检测到了SMV。有趣的是，在进行1分钟获毒刺探的蚜虫中，RT-PCR检测到SMV的比率（31.67%）与传毒率（34.72%）相符。讨论了RT-PCR在检测非持久性传播病毒中的实际应用及其对病毒流行病学的意义。
